Reversing-gear for internal-combustion engines



H. WIEDERKEHR. REVERSING GEAR FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED NOV. 3 1920.

Patented oet. 18, 1921.

UNITED STATES PATENT OFFICE.

HANS WIEDERKEHR, OF ZURICH, SWITZERLAND, ASSIGNOR T0 THE FIRM OFSCHWEIZERISCHE LOKOMOTIV & MASCHINENFABRIK, OF WINTERTHUR,

SWITZERLAND.

REVERSING-GEAR FOR INTERNAL-COMBUSTION ENGINES.

Application tiled November 3, 1920.

To all whom t may concern Be it known that I, HANS WIEDERKEHR, a citizenof the Republic of Switzerland, residing at Zurich, Switzerland, haveinvented certain new and useful Improvements in Reversing-Gears forInternal-Combi1stion Engines; and I do hereby declare the following tobe a clear, full, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same, reference being had to the accompanying drawing, and toletters or figures of reference marked thereon, which form a part ofthis specication.

This invention relates to improvements in reversing gears for internalcombustion engines.

With internal combustion engines which are provided with double cams, e.for ahead7 and astern running, it is known to lift the rollers coactingwith the cams olii' the latter in order to shift the cam shaftunrestrictedly in' the axial direction. When performing thismanipulation the springs of the spring loaded valves have to becompressed, which performance necessitates a considerable expenditure ofenergy with multicylinder-motors of a medium Size. This lifting requiresa great ratio of trans mission and therefore involves considerable timefor performing the reversal, for this reason it has been proposed to usean auxiliary motor driven by compressed air or pressure oil for carryingout the reversing operation whereby the long periods inherent to areversal by hand are shortened.

l According to the present invention the above mentioned drawback iseliminated in a very simple manner in combining an auxiliary spring withthe cam-lifting device which compensates the increasing antagonisticpressure of the springs actuating one or more valves.

One mode of carrying the invention into effect is shown by way ofexample in the accompanying drawing.

In this drawing W denotes the cam shaft adapted to be displaced in theaxial direction, on said shaft two cams V and R for ahead and asternrunning respectively are provided, which, in a known manner, actuate thespring-loaded valve E by means of Specification of Letters Patent.

Patented Oct. 1S, 1921.

serial No. 421,575.

the roller O and the rocking lever H. Previous to displacing thecam-shaft W for reversing purposes, the shaft Y is turned byl means ofhand wheel D, worm S and lever X whereby the lever Z moves the roller AObeyond the range of the path of the revolving cams, whereupon thedisplacing of the cam shaft JV in the axial direction can he performedunrestrictedly. The positions of the parts H, X, B and F after thelifting has been performed are shown diagrammatically in chain dottedlines. The turning moment exerted by the valve spring C on the shaft Ywhen lifting the roller is compensated in every position of the rockinglever H by an auxiliary spring F acting upon the lever B, as the varyingpressure of the valve spring Eis compensated by the varying leverageref-A1 of the direction in which the auxiliary spring acts.v

Obviously the number of leversZ provided on the cam shaft may varyaccording to the number of valves.

I claim: v

l. A reversing gear for internal combustion engines, comprising a camshaft adapted to be axially displaced and provided with ahead and asterncams, a roller coacting with either of said cams7 a rocking lever fortransmitting the cam action to a spring-loaded valve, lifting meansoperatively connected to said roller, and an auxiliary spring combinedwith said lifting means to compensate the antagonistic action of thevalve spring.

2. A reversing 'gear for internal combustion engines, comprising a camshaft adapted to be axially displaced and provided with ahead andasterrr cams, a roller coacting with either of said cams, a rockinglever for transmitting the cam action to a spring-loaded valve, .meansoperatively connected to said roller to move the latter out of the rangeof the path of the rotating cams, and an auxiliary spring connected to alever forming part of said means whereby the leverage of the action ofsaid auxiliary spring alters so that the antagonistic actionV of thevalve spring is always compensated. In testimony that I claim theforegoing as my invention, I have signed my name.

HANS WIEDERKEHR.

roo

